Soluciones irrigantes

D eloche an d Seron (1984a,b) su g g e ste d th a t a sim ila r stru c tu ra l organisation underlies the num ber series and also other linguistic elem ents w ith a characteristic order. It is possible th at C.G.’s deficit for n u m b ers m ay be explicable in term s of a deeper problem w ith ordinal structures generally. In the follow ing tests, the ability of C.G. to reproduce non-num erical sequences was assessed.

Reciting non numerical sequences. C.G. w as ask ed to recite five non- num erical sequences - seasons of the year, m usical notes, m onths of the year, days of the w eek, and letters of the alphabet. The p a tien t w as able to recite correctly just the four seasons and the seven m usical notes ("Doh, ray, m e etc."). Perform ance on the other sequences was poor - letters, "c,a,p...no more"; days of the week, "Monday, W ednesday, Friday, Saturday, Sunday"; m onths of the year, "December, January, June, May, August").

"W hat comes next?". C .G .'s in ab ility to p ro d u c e co m m on sequences correctly m ay been d u e to som e failure to retrieve accurately an d com pletely in fo rm atio n th at is still in sem antic m em ory. Two tasks w ere d ev ised to m inim ise the retrieval problem for the three sequences w hich she failed to recite correctly. The first task w as equivalent to the "W hat comes next?" test for the nu m b er series described above. In the non-num erical version, the experim enter said the nam e of an elem ent from the sequence (e.g "Monday"), an d the patient w as asked to give the next one in the sequence. T w enty-five elem ents w ere presented (7 days, 12 m onths and 6 letters). N one of C.G.'s answ ers w ere correct, (e.g. For the letter A, she said, "I don't know...maybe p").

Triplet sériation. In the second task the p atien t w as p resen ted auditorilly w ith 30 triplets taken from the three sequences. Ten triplets consisted of letter nam es - e.g. u, a, g; 10 triplets consisted of days of the weeks - e.g. M onday, Friday, W ednesday; an d 10 triplets of m onths of the year - e.g. M arch, January, June. Three w ords w as well w ithin C.G.'s span of im m ediate w o rd repetition. H er task w as to repeat in the correct order the elements of the triplet. C.G. m anaged just 1 correct answ er from 30.

2.36a Summary

Some familiar sequences, like the alphabet, days of the w eek and m onths of the year (but not the m usical notes and the season of th e year), also pose problem s. She is quite unable to give the next elem ent in these sequences. There are how ever, im portant differences from her perform ance on equivalent tasks w ith num bers: w here she know s the num ber nam es, she is alm ost alw ays able to p ro v id e correct ordinal inform ation, w hereas, even th o u g h she can recite, say, five days of the week in the right order, w ith gaps, she cannot say w h at comes next if given one day as a prom pt.

2.37 Tests of know ledge of quantities

N u m b ers are p erh ap s m ost often u sed to d en o te q u an tities, an d the m ean in g of num ber term s entails their p ro p er o rd erin g w ith respect to the quantities (cardinal values) denoted by them. It w as clear from tests of num ber m ean in g , th at C.G. show ed a total im p airm en t for the card in al values of num bers above 4. It is possible that this severe deficit could be explicated in terms of a m ore general cognitive im p airm en t in dealing w ith q u an tities. In the following tasks, C.G.’s ability to deal w ith non-num erical quantities w as assessed.

2.37a Size judgm ent task.

The first question w as w hether C.G could deal w ith size relations. Sixty pictures of fam iliar objects w ere assem bled, divided in to 5 categories - anim als, fruits and vegetables, vehicles, m usical instrum ents an d household item s, w ith 12 objects per category. The pictures were realistic black an d w hite draw ings all h av in g roughly the sam e pictorial size; so, for exam ple, a cam el and a spider hav e ro u g h ly the sam e size in the picture. Pairs of p ictu res from the sam e category were presented, and C.G. was asked to judge which object w as the bigger in real life. The p atien t resp o n d ed p rom ptly and w ith o u t h esitatio n an d her perform ance was flawless for all categories.

2 .37b Quantity sériation tasks

Pictures. The same kind of m aterials w as used as in the size judgem ent task. This tim e three pictures belonging to the same category w ere presented and the patient was asked to point the pictures of the three objects in order of the size of object denoted by the picture. A gain her perform ance w as perfect for all categories. C.G. w as also asked to order triplets of playing cards in term s of their usual values. She w as able to do this for the picture cards and for the cards 2 to 4; for other values, no triplet w as correctly ordered.

Measure terms. The p a tie n t w as p resen ted w ith tw o sp o k en m easure term s and w as asked to decide w hich of the tw o term d e n o te d the greater quantity. Terms denoting w eight, (e.g. gram , kilo, tonellata, quintale) or length, (e.g. m eter, centimetre, kilometre) w ere used. H er score w as lOout of 10 c o rre c t.

Judgm ents of ''More". The p a tie n t w as asked to d ecid e w hich of tw o physical quantities w as "more". For exam ple, w ere there m ore coffee beans or grains of salt in a tea cup? C.G.'s perform ance w as again flawless: she gave 13 correct answ ers to 13 questions. A second set of questions involved tim e terms. For exam ple, "In a year are there m ore seasons or m ore m onths?", or "In a day, are there m ore hours or minutes?". By contrast to physical quantities, she was able to correctly reply to just 4 out of 15 questions.

2.37c Summary

Generally, C.G. appears to have retained the ability to deal w ith physical q u a n titie s, an d can ju d g e w hich of tw o is larg er, e ith er w h e n p resen ted pictorially or verbally.